Corrugated sheet



Oct. 6, 1964 A. J. HASTINGS 3, 7

CORRUGATED SHEET Filed NOV. 16, 1961 5 ShGGtS -Shee't l INVENTOR. ALLANJ HASTINGS ATTORNEY Oct. 6, 1964 A. J. HASTINGS 3,

CORRUGATED SHEET Filed Nov. 16, 1961 3 Sheets-Sheet 2 FIG.4

FIG. 7

qlllllll/llllllll INVENTOR 32 a 30 ALLAN J. HASTING'S 1 Fl 8 50% f gATTORNEY United States Patent 3,151,947 CORRUGATED SHEET Allan J.Hastings, Los Angeles, Calif., assignor to The Boeing Company, Wichita,Kane, a corporation of Delaware Filed Nov. 16, 1961, Ser. N 152,764Claims. (1. 29-489) My invention relates to a new corrugated sheetmaterial of novel construction including the formation of semipyramidalcorrugations rather than conventional untapered corrugations.

The sheet material is useful in large spans, such as 50 feet, and incantilevered structures, such as may be found in roofs of buildings. Italso applies to panels used in buildings wherein the corrugatedconfigurations may extend the full length of a panel or may be only afew inches long repeated in series from end to end of a panel. A primaryobjective of the invention is to provide better structuralcharacteristics in corrugated panels for the above describedapplications. This is achieved by the use of triangles, intwo-dimensional terms, or by the use of semi-pyramidal forms built up bysuch triangles, in threedimensional terms, which may be said to beinherently strong configurations.

Other objectives include: to provide a pleasing sheet appearanceadaptable for architectural use in exposed areas; to provide maximumstrength to size and weight, and maximum strength to cost; to devise acorrugated structure having considerable flexibility in designapplication; to devise a prefabricated structural element to reducebuilding erection costs; to provide a construction economicallymanufactured and easily handled, including the ability to be stacked inan envelope of minimum size for transportation and storage.

Further advantages and objectives of my invention will be understoodfrom the following description and from the drawings in which:

FIGURE 1 is a top perspective view of a specific embodiment of my newcorrugated sheet.

FIGURE 2 is a bottom perspective view of two corrugated sectionsintegrally formed.

FIGURE 3 is an end view of the sheet.

FIGURE 4 is a plan view of the lines of ridges and grooves as they wouldappear if a corrugated sheet of the invention were flattened orindicating where folds would be made in a flat sheet to produce mycorrugated sheet.

FIGURE 5 is a plan View showing a first corrugated sheet and portions ofanother sheet joined by connecting means, and indicating a tieing orsupporting plate.

FIGURE 6 is an enlarged perspective view of a connecting member andportions of a plate.

FIGURE 7 is an enlarged fragmentary view, partly in section, showing thejoining of two sheets by the connecting member of FIGURE 6.

FIGURE 8 is a view similar to FIGURE 7 using a modified connectingmember.

FIGURE 9 is a top View of corrugated sheet of the invention fanned intoan annulus.

FIGURE 10 is a top perspective view of a portion of the annulus ofFIGURE 9.

INTRODUCTION One application of the invention is for roofs or other spanor cantilevered structures where costs can be reduced and facility ofdesign can be furthered if the materials are particularly adapted forspanning and cantilevering. Structures other than thin-shell assembliesrequire sections as deep or deeper than 4 feet, depending on dead-loadmaterial stresses, for clear-spanning distances as great as 50 feet.Such deep sections have little use other than form- Fatented Get. 6,1964 ing the structural members and housing heating ducts and wiring.

Thin-shell construction follows the stress curve and allows greater spanwith less depth. A disadvantage of various thin-shell constructionspreviously used is the extensive fabrication required to produce thefinished prodnet. This automatically raises the cost per unit area.

Spans no greater than 12 feet cause little difiiculty, but the greaterthe span beyond this general limit the more difiicult the fabricationand the deeper the section required in roof construction. Whereas liftslabs, curtain walls, and modular aluminum panels have good applicationas prefabrications and labor-saving systems to minimize the cost oferecting buildings, minimizing roof costs has remained a difficult area.

The present sheet metal assemblies are adapted to span relatively longdistances with minimum material. All the material is structural insteadof being partly only a covering. This means that the major load carriedis live load instead of dead-load of the structure itself.

As before indicated, the corrugated construction is usable not only inroofs but in smaller constructions, such as wall panels, and the lowerlimit is in applications where the corrugated pattern repeats itselffrom end to end of a panel every several inches. Such an applicationwould include luggage racks for aircraft where it is desirable tomaximize spans and minimize material bulk and weight. In some designsthe appearance may be as much a consideration as structuralcharacteristics and the corrugated sheet of the present invention isbelieved to be of pleasing appearance.

The standard sheet may be 4' x 8 and the standard material may bealuminum. However, the length and width may be considerably larger forsome applications depending on the lengths and widths of available sheetmaterial to be formed and the availability of large size machines, suchas presses, capable of forming such longer lengths. The corrugated sheetcan be made of various materials such as aluminum, low-grade steel,resin-impregnated Fiberglas, wood pulp and plastics. One productionmethod for metal is the use of progressive doubleacting dies. A form ormold is used with Fiberglas wood pulp and plastics.

FIGURES 1-5 Corrugated sheet 20 may be formed from flat sheet or may bemolded in corrugated shape, as normally would be done when the materialis Fiberglas wood pulp or plastic. FIGURE 4 can be interpreted asshowing the lines on which a flat sheet should be folded or as showingwhat a material corrugated when formed would look like if flattened. Inthe flat condition the lines 1-12 in FIG- URE 4 represent the tops ofridges and the bottoms of grooves and they represent the lines on whichfiat sheet material would be bent to form corrugations.

When a corrugated sheet is viewed in flattened condition or when acorrugated sheet is examined in top and bottom views: (i) serially oddlines, 1, 3, 5, 7, 9, l1 would be substantially parallel; (ii) seriallyeven lines 2-, 4, 6, 8, i9, 12 interfingered therewith wouldsubstantially intersect the odd lines i.e., line 2 would intersect lines1 and 3 etc. (if the ends of the sheets shown were chopped off, thelines in the material would not intersect although extensions of thelines would intersect); (iii) the even lines would form a substantiallycontinuous zigzag; (iv) non-adjacent even lines would be substantiallyparallel, i.e., lines 2, 6 and 10 would be substantially parallel toeach other and lines 4, 8 and 12, would be substantially parallel toeach other. For

Tr-ademark of Owens-Corning Fiberglas Corp. of New York, N.Y.

- sheet.

purposes of convenience of description in the specification and claims,serially odd and even lines are described; but. this does not mean thatnumbering must start on the first line at the side edge of a panel,e.g., the series may be considered to start at the second line oranother convenient, applicable line on the face of the corrugatedAlternate lines that are parallel would be considered the odd lines.

In the corrugated condition of sheet 20: (i) odd lines are the tops ofridges on a first side of said sheet and are the bottoms of grooves onthe second side of said sheet; (ii) even lines are the bottoms ofgrooves on said first side of said sheet and are the tops of ridges onthe second side of said sheet; and (iii) each odd line and the adjacenteven lines together form three-dimensional outlines which are ridges onsaid first side of said sheet and are grooves on said second side ofsaid sheet and which are of V configuration transversely of saidcorrugation-s and which taper substantially to zero longitudinally ofsaid corrugations, the adjacent three-dimensional outlines beingjuxtaposed and being faced in opposite directions longitudianlly of saidcorrugations with pointed ends and broad ends of adjacentthree-dimensional outlines juxtaposed.

Another way of describing the corrugated sheet is to say:

(a) The corrugations 21 are formed by a series of juxtaposed identicalthree-dimensional outlines forming ridges on the upper surface of thesheet. Lines 4, and 6 form 'a three-dimensional outline which is a ridgeon the upper surface in FIGURE 1 and a groove on the lower surface inFIGURE 2.

(b) The three-dimensional outline is of V configuration transversely ofthe corrugations and tapers to zero longitudinally of the corrugation,e.g., planes normal to lines 4, 5 and 6 show V configurations and lines4, 5 and 6 taper to zero or intersect at the right hand side in FIGURE1, forming tapered ridges on the upper surface of the sheet and taperedgrooves on the lower surface of the sheet. Adjacent juxtaposedthree-dimensional outlines face in opposite directions longitudinally ofthe corrugations. The three-dimensional outlines could be termedsemi-pyramids in that each is a half of a pyramid (laid on its side asviewed) having a four-sided base and great height (in a horizontaldirection as viewed) in comparison to the dimensions of the base. (c)The three-dimensional outlines on their lines of meeting form grooves onthe upper surface of the sheet and form ridges on the lower surface ofthe sheet, i.e., lines 4 and 6 are the bottoms of grooves in the topview of FIGURE 1 and are the tops of ridges in the bottom view of FIGURE2.

The basic two-dimensional elements making up the corrugation aretriangles that may be all identical. If a large structure such as abridge bed were to be formed with this corrugated construction, onemethod of fabrication would be to transport sufficient numbers oftriangular sheet metal plates of identical sizes and to weld themtogether on the site to form the corrugated structure shown in thepresent drawing. Triangles are good structural building blocks, i.e.,trusses are formed mostly by triangles.

The basic units in three-dimension are semi-pyramids (upright when thesheet is upright) formed from the joinder of two elongated righttriangles. A pyramid is one of the strongest structural shapes and thepresent corrugated sheet may be analyzed as having some of thestructural properties of pyramids. Although the corrugations are shownas V configurations formed by planar surfaces, curved, taperedcorrugations or channel-shaped tapered corrugations could be used. The Vconfigurations have the best structural properties.

For spanning and cantilevering applications, corrugated sheet 20 is bestapplied with the top and bottom relationships shown in the drawings(rather than inverted). The

3. bottom surface 22 is fiat (see FIGURE 3) and the upper surface 24-may be said to be saddle-shaped in having more height at its ends thanin the middle. The flat surface 22 is adaptable for bonding of a skinthereto.

The sheet material has various applications other than for roofs. As ahighway or airstrip base, the sheet material can be laid directly onlevel ground and then asphalt or concrete placed over it. It has varioususes as panels in products. Sheets can be used for vertical structuralwalls, but the choice may be dictated as much by appearance as bystructural considerations. In use for bridges, a covering such asconcrete may be poured over the sheet and it is possible to use thesheet as a form to be removed after the concrete is set.

In roof applications a sprayed material, such as acoustical plaster forinsulation and fire-proofing, can be applied on the bottom surface. Acoating also can be applied to the upper, outer surface, i.e., thingauge aluminum should have a protective coating as against hail.

FIGURE 2 and 20". This is because the forming of the upper saddlesurface tends to pull in the upper end edges so that the end surfacestend to be non-vertical.

It will be understood that the over-all length of two sections iii, 2%may vary between 16 feet or more and 6 inches or less. The width islikewise variable and sheets may be formed of greater Width than length.One unobvious feature of the construction is the capability of varyingthe density or strength of the corrugated sheet by bringing lines I, 3,5 closer together or moving them farther apart. If a resilient materialis used to form the sheet 20, such broadening or narrowing of the sheetcan be done on the construction site and will only require means ofuniform stretching or compressing, and means to hold them in suchcondition, i.e., the shape and the FIGURES 5-8 FIGURE 5 shows aconstruction in which sheets 20" and 20"" are separate and are joinedtogether by connecting members 30. Various types of connecting meanscould be used. The connector 30 in FIGURE 6 has good strengthcharacteristics in relation to its weight. It has three side walls andhas internal flanges 32 directed normally to the side walls. Connectors30 can be cast or can be fabricated from metal stock by welding.Connectors 30 are secured by bolts 34 to a plate 36. If sheets 26 and 20are joined in the middle of a span, plate 36 merely ties connectors 30together. If instead the joint is at the location of a supporting wall,plate 36 may become the upper flange of an I-beam and have the functionof supporting the connectors; and hence the sheets. Connectors 30 alsocan be used at the end of a corrugated sheet to secure or support thesheet in end assemblies where another sheet is not joined to the firstsheet.

FIGURES 7 and 8 show two methods of securing the sheets to connectingmember 30. In FIGURE 7 the sheets are abutted on the outside of theconnector and secured in place by rivets 40. In FIGURE 8 the side wallsof connector 3i) are formed with recesses 42 receiving the edges of thesheets which may be adhesively bonded in place. It will be understoodthat there. are many other possible ways to secure sheets together, tohold the corrugations against unfolding, and to support the assembly.

The semi-pyramid structural shapes, of course, are made stronger byconnectors 30 which, in effect, complete the semi-pyramid base or bridgeacross the V transverse outline. If the corrugations are formed by aprocess and with a material not forming a precise enough shape, theinstallation of connectors 36 can bring the bases of the corrugations toproper configuration. The corrugated material can be made resilient withthe intention of varying density and strength by spreading or bringingtogether the corrugated ridges and grooves as a function of theconnecting means, i.e., as the upper angle of connector 30 in FIGURE 6is reduced, the corrugated structure will be compacted to a denser,higher load carrying condition, and the reverse will occur as the upperangle of connector 30 is increased.

The ends of adjacent corrugated sheets, of course, could be merelylapped, in the manner that ordinary corrugated sheet is used on apitched roof; but such lapped construction would not take full advantageof the structural properties of my corrugated sheet. It is significantthat conventional corrugated sheet is usually used on a roof merely as acovering contributing little to carrying loads in fact being primarily adead-load, that must be added to the other loads a supporting structuremust carry. My corrugated sheet commonly will have the oppositeapplication: it will be the primary load carrying member for a roof orthe like.

FIGURES 9-10 FIGURES 9 and 10 show the fanning of the sheets shown inthe previous figures into partly or completely annular structures. Theminimum size of the opening 59 in the annulus is determined by themaximum compacting of the corrugated sheet about the opening. As theridges and grooves on the perimeter of the annulus are made sharper (onthe right-hand side in FIGURE 10), more corrugated sheet Will berequired and the structure about the annulus opening (on the left-handside in FIGURE 10) will become denser. The perimeter of the annulus canbe brought to nearly planar condition if little load is to be carriedand can be sharply grooved if sizable loads are to be carried. Furthervariations in density can be accomplished by corrugating a partlyannular sheet on radial rather than strictly parallel lines.

The sheet from which the annulus is formed would have great width toform an annulus by one piece and the annulus is more likely to be formedfrom several sheets joined at their edges. There are many ways ofsecuring the edges such as by welding, lapping and riveting or byconnecting with special connectors. Normally the an nular structure willbe substantially or completely cantilevered and the assembly is welladapted for such application as the densest structure is in the centerwhere the maximum load will be carried. Whereas it is possible to moldthe material into the annular form, it commonly will be formed bybringing together one edge of corrugated sheet such as is shown inFIGURE 1 and spreading the other end. Depending on the resiliency of thematerial, partly a function of the nature of the material and partly afunction of the material thickness, it would be possible to bothout-fold the sheet for erection and to in-fold the structure fordisassembly, in the manner of a fan or umbrella, to permit reuse.

The corrugated sheet is believed to meet the design objective of lowertotal cost in erecting buildings and the like, to provide individualstructural sheets which can be made in a size to be readily handled byone man, to minimize erection time, to maximize structural capabilityversus weight, and to provide flexibility of usage and adaptability tofunctional architectural design. The construction is susceptible ofbeing constructed of high quality materials to form permanent structuresand being con- 6 structed of low cost materials such as paper, fabric,and plastics for temporary uses.

Having thus specifically described my invention, I do not Wish to beunderstood as limiting myself to the precise details of constructionshown, but instead wish to cover those modifications thereof which willoccur to those skilled in the art from my disclosure and which fallwithin the scope of my invention, as described in the following claims.

I claim:

1. A sheet material structure forming at least part of an annulus byfanning corrugated sheet material having the following configurationbefore fanning:

(a) a series of juxtaposed corrugations formed in said corrugated sheetmaterial by a series of juxtaposed identical three-dimensional outlinesforming ridges on a first side of the sheet and forming grooves on thesecond side of said sheet,

(b) each three-dimensional outline being of V configuration transverselyof the corrugations and tapering substantially to zero longitudinally ofthe corrugations with adjacent juxtaposed three-dimensional outlinesfaced in opposite directions longitudinally of the corrugations, and

(c) said three-dimensional outlines on their lines of meeting forminggrooves on said first side of said sheet and forming ridges on saidsecond side of said sheet.

2. An annular sheet material structure having a series of radiallydirected, juxtaposed corrugations, comprising:

(a) said corrugations being formed by a series of juxtaposedthree-dimensional outlines forming ridges on a first side of the sheetmaterial and forming grooves on the second side of said sheet material,

(b) each three-dimensional outline tapering substantially to zerolongitudinally of the corrugations with adjacent juxtaposedthree-dimensional outlines tapering in opposite directionslongitudinally of the corrugations, and

(c) said three-dimensional outlines on their lines of meeting forminggrooves on said first side of said sheet and forming ridges on saidsecond side of said sheet.

3. An annular sheet material structure having a series of radiallydirected, juxtaposed corrugations, comprising: at least part of thecorrugations being tapered, corruga tions tapered in a first directionalong the corrugations being interfingered with corrugations tapered inthe opposite direction along the corrugations.

4. The improvement in an article formed of sheet material configured bya plurality of corrugated sections arranged serially longitudinally ofsaid article and each of said sections having a series of juxtaposedcorrugations, comprising:

(a) said corrugations of each of said sections being formed by a seriesof juxtaposed identical threedirnensional outlines forming ridges on anupper surface of said sheet material and forming grooves on a lowersurface of said sheet material,

([2) each of said three-dimensional outlines being of V-shapedconfiguration transversely of said corrugations and taperingsubstantially to zero longitudinally of said corrugations with adjacentsaid juxtaposed identical three-dimensional outlines being faced inopposite directions longitudinally of said corrugations,

(c) said juxtaposed identical three-dimensional outlines on their linesof meeting forming grooves on said upper surface of said sheet materialand forming ridges on said lower surface of said sheet material,

(d) connecting means adjacently connecting said corrugated sectionstogether to form a sheet of material, said connecting means including aplurality of transversely aligned triangular connecting memberspositioned on said lower surface of said sheet material, member disposedbeneath and connected to said transeach of said triangular connectingmembers being dis- Versely aligned triangular connecting members.

posed in a longitudinally aligned pair of said grooves formed by each ofsaid three-dimensional outlines References Clted 111 the file 0f thlsPatent in said adjacent corrugated sections, and 5 UNITED STATES PATENTS(e) fastening means securing said adjacent corrugated sections to saidtriangular connecting members. ggifi :5 3 5. The improvement in anarticle as set forth in clalrn 2,963,128 Rapp Dec- 6, 1960 4, furthercomprising a transversely extending support

2. AN ANNULAR SHEET MATERIAL STRUCTURE HAVING A SERIES OF RADIALLYDIRECTED, JUXTAPOSED CORRUGATIONS, COMPRISING: (A) SAID CORRUGATIONSBEING FORMED BY A SERIED OF JUXTAPOSED THREE-DIMENSIONAL OUTLINESFORMING RIDGES ON A FIRST SIDE OF THE SHEET MATERIAL AND FORMING GROOVESON THE SECOND SIDE OF SAID MATERIAL, (B) EACH THREE-DIMENSIONAL OUTLINETAPERING SUBSTANTIALLY TO ZERO LONGITUDINALLY OF THE CORRUGATIONS WITHADJACENT JUXTAPOSED THREE-DIMENSIONAL OUTLINES TAPERING IN OPPOSITEDIRECTIONS LONGITUDINALLY OF THE CORRUGATIONS, AND (C) SAIDTHREE-DIMENSIONAL OUTLINES ON THEIR LINES OF MEETING FORMING GROOVES ONSAID FIRST SIDE OF SAID SHEET AND FORMING RIDGES ON SAID SECOND SIDE OFSAID SHEET.